Creating the Perfect Sky

Architecture graduate students build artificial sky to shine on models

By Tara Roberts

Photos by UI Photo Services

A tall, rocket-ship-shaped structure stretches into the rafters in the back corner of the University of Idaho’s Art and Architecture South studio. Inside, its sloped white walls reflect the gentle glow emanating from a skylight in the top.

The structure is the world’s first passive artificial sky – a tool that uses natural light to accurately predict how daylight will affect the interior appearance of new buildings.

Bruce Haglund and his team of architecture graduate students are in the final stages of constructing the artificial sky, which Haglund has been working on since 2009, along with more than 30 student-researchers. Unlike traditional artificial skies, which use electric light, this one does not require special fixtures or mirrors.

Architects use artificial skies to test models of proposed designs to understand how light, dark, glare and other qualities will appear in the final building, Haglund explains.

An artificial sky’s light must be three times as bright at the zenith as at the line representing the horizon – the international definition of a perfectly overcast sky, and the worst-case scenario for daylighting. The UI team had to ensure their sky provided this precise lighting distribution under all outdoor sky conditions while using only the skylight and the shape and color of the interior panels.

“We didn’t know what shape this had to be, so student teams built scale models and tested them,” Haglund says. Two of the four teams came up with cone-shaped structures that met the performance goal.

The skylight, donated by Solatube, is highly efficient and reflective, gathering light from the entire sky. Regardless of the weather outside, the light inside the UI artificial sky will allow accurate measurements.

In addition to requiring no electricity, the UI artificial sky is sustainable because it uses simple materials and modular panels that can be detached and reassembled anywhere.

“We were very conscientious of how we used the materials,” Edde says.

This semester, Haglund’s graduate students – Edde, Brenda Gomez and Dan Flesher – are calibrating and adjusting the artificial sky and testing the instruments and software that gather information from the models tested inside.

“This really is an asset to the university,” Edde says. “This will help us develop our concepts and design them through tangible, physical models.”

A grant from the UI Seed Grant Program paid for the sky’s materials and monitoring equipment, as well as allowed Haglund and past students to present their project at the Passive and Low-Energy Architecture Conference in Lima, Peru.

Haglund will present the project at the Professional Lighting Design Conference in Copenhagen this month, and his current team of students will present at the Association of Architectural Research Consortiums joint international conference in Hawaii in February.

The architects and students who have encountered the design so far have been fascinated by it, Gomez says – and it’s still intriguing to the people who built it.

“Knowing this is the only one in the world, it’s really amazing to work on it and learn from it,” Gomez said.